Steam vacuum-pump.



W. R. EMERSON.

STEAM VACUUM PUMP. .QPPLIUATION FILED MAY 22, 1 907.

921 ,967. Patented May 18, 1909 a moemfoz we M eases MDCLMAQ THE NORRIS PETERS-CO), wnsnmaron. n. c,

WILLIAM R. EMERSON, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO THE EMERSON STEAM PUMP COMPANY, OF ALEXANDRIA, VIRGINIA, A CORPORATION OF VIRGINIA.

STEAM VACUUM-PUMP.

Specification of Letters Patent.

Patented May 18, 1909.

To all whom it may concern:

Be it known that I, WILLIAM R. EMERSON, of Washington, in the District of Columbia, have invented a certain new and useful Improvement in Steam Vacuum Pumps; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the characters of reference marked thereon.

This invention relates to improvements in steam vacuum pumps, the invention being particularly applicable in pumps having a vertically arranged cylinder or cylinders with inlet and outlet passages at or near the bottom and a steam inlet at the top.

The objects of the invention are to provide a pump of this type which will be automatic in its action and in which there shall be no valve operating mechanism of any character associated with the valves.

In carrying the invention into practice, the pump cylinder communicates at a'point near the bottom with a supplemental chamber extending a short distance above the communicating passage and into which chamber the steam may blow at the instant when the water level has been lowered to the top of said passage, thereby initially reducing the pressure in the pump chamber; this reduction in pressure being augmented by the instant condensation of the steam entering the supplemental chamber due to the commingling and churning of the steam and cold water in the chamber above the communicating passage.

The reduction of pressure in the pump chamber is utilized to close the steam inlet valve and the increase in pressure due to the inrush of water to fill the vacuum left by the condensation of the steam is utilized to open the said valve, the operation of the valve being thus made entirely independent of any mechanical operating means or of the steam pressure in the steam supply.

The type of steam valve adopted, is a simple cylindrical valve having a plane seat at the bottom for closing the steam entrance, said valve, however, is mounted in a housing having a somewhat higher COG'IIlCIGIll? of expansion to insu e the freeing of the valve, whenever steam is turned on.

Referring to the accompanying drawings:

Figure 1 is a side elevation of a pump embodying the present improvements, and with the condenser spray pipe partly in section to show the check valve. Fig. 2 is a sectional view in a central vertical plane. Fig. 3 is a section through the upper end of the chamber and valve in a Vertical plane at right angles to Fig. 2.

Similar characters of reference in the several figures indicate the same parts.

The main pump cylinder or chamber A is preferably substantially cylindrical throughout the greater part of its length, the diameter being gradually reduced above the cylindrical portion and terminating at the top in a relatively small central opening surrounded by a flange S on which the steam valve and its casing are mounted as will presently appear.

Near the bottom of the chamber and at one side thereof is the supplemental chamber T, the communicating passage between the chambers being below a narrow partition T separating the two chambers. The lower outer wall of the supplemental chamber is curved as at T to direct the water entering through the communicating passage upwardly with a view to reducing resistance to the discharging water and to insure a churning or whirling action in the supplemental chamber when steam blows into the same.

The intake pipe L is preferably located in alinement with the main pump cylinder or chamber, its upper end being secured to a cap K bolted to the bottom of the cylinder. Said cap is also adapted to clamp the base flange of the brass intake valve spider I on which the rubber disk valve H seats and is held by a central stem and springUin the well understood manner.

The discharge pipe D is preferably con.- nected with the supplemental chamber T by a valve casing B adapted to be bolted'to the top of said chamber and to clamp the base flange of a brass valve spider E having a rubber disk valve F held in place by a central stem and 'spring C.

The steam entrance valve is preferably a cylindrical valve P of iron or similar metal having a series of packing grooves, and mounted to work vertically in a brass or gun metal casing O. The lower end of the valve is fiat or plane and seats squarely on a washer or flat annulus N clamped between the casing O and flange S of the pump cylinder. A cap serves as the stop for limiting the upward oropening movement of the valve and bolts passing through the cap, casing and annulus clam the whole firmly t0 the upper end of the cy inder. An annular steam passage 0 is formed in the lower end of the casing around the valve and steam is admitted thereto through a steam pipe connected with the steam entrance y. The arrangement is such that when the valve is down, the steam is cut off and steam pressure in the steam supply does not tend to open the same. When the valve is up an opening for the steam beneath the valve exists of practically the same capacity as the inlet pipe. The passage beneath the valve is a long one and only a very slight movementof the valve is necessary to give a full opening. The diameter of the valve is made considerable and its area exposed to the pressure in the cylinder and the cross sectional areaof the passage from it to the cylinder are both greater than the cross sectional area of the steam passage to. and ast the valve, in order that the valve may 0 ose quickly when the pressure within the cylinder is reduced even slightly and as readily open when the pressure within the pump cylinder rises but little above atmospheric pressure, the result being a quick action pump very economical in its use of steam. By providing a plane valve seat and valve face for cooperation therewith, expensive fitting, grinding and adjusting are avoided as the valve will seat on the annulus even though the vertical axis of the valve and the annulus are not absolutely concentric. Below the valve seat but in the upper part of the cylinder is an air inlet controlled by a check valve V, adapted to let in a small quantity of air during the inspiration period but to close and prevent escape of steam or water during the expiration period. A petcock V may be employed to regulatc'the quantity of air admitted.

A spray condenser connection in the form of a pipe X is provided between the valve chamber B ordischarge pipe and body of the cylinder A. This spray condenser con nection is inclined downwardly from the cylinder and provided with a check valve :0, whereby water may be sprayed into the cylinder when the pressure therein is less than the pressure in the outlet pipe, but no steam or water can pass through in the opposite direction. By making the connection inclined no water will drain out of the connection after the pressures equalize or that in the cylinder predominates.

In operation, and assuming that the pump has been primed or filled as may be easily done by a hand manipulation of the throttle valve, the pressure within the cylinder will hold. the steam admission valve open, allow ing steam to enter freely to drive the water trom the chamber into and through the supplemental chamber to the out-take. When the water level in the cylinder reaches the top of the o )ening communicating with the supplementa chamber, steam blows into the latter and is instantly condensed thereby lowering the pressure in the cylinder. This reduction in pressure may be very marked inasmuch as a large volume of steam will. blow into the supplemental chamber and the condensation for a short time will greatly exceed the capacity of the steam intake to supply live steam, the result being that water from the valve chamber B will spray back into the. cylinder through the connection X, thereby completing the condensation of the steam in the cylinder and creating a vacuum. The initial effect of the reduc- 8 tion of pressure in the cylinder is to close the steam inlet valve by atmospheric pressure, this being followed by the inspiration period when the water enters through the intake and a small quantity of air enters through the snifilingvalve V. The momentum of the entering water compresses the air in the top of the cylinder and acting on the large bottom face of the steam inlet valve 0 ens the latter for the admission of steam ano a repetition of the described operations.

The steam admission valve it will be noted is of such construction that'its operation is certain and eiiective with either high or low pressures of steam, in other words the valve is controlled exclusively by the diiie-rences between atmospheric pressure and the pressure Within the pump cylinder. In this respect it differs from those structures in which the steam pressure in the steam supply operates on the valve with a tendency to open or to close the same, for in pumps of the latter construction successful operation depends in a large measure upon the relative pressures in the steam supply and pumpcyls 11 inder or between the steam supply pressure and atmospheric pressure, and a variation in the steam pressure, above or below that for which the parts are designed. or set Willprevent successful operation of the pump.

In connection with the operation of the steam supplyvalve, it is to be noted that the whole bottom face operates as a piston face exposed to the pressure in the pump cylinder and no part of said face operates as a piston 120 exposed to the pressure in the steam inlet. The external or atmospheric pressure plus the weight of the valve keeps the valve closed, save when the cylinder pressure exceeds atmospheric pressure sufficiently to 125 overcome the gravity of the valve. While the valve might be liable to stick ifthe pump be left idle for any length of time, the formation of the valve casing of a metal having a highercoefiicient of; expansion than the valve 1 3 insures a prompt freeing of the latter as the throttle valve is opened and the valve casing is warmed. u

It is preferred tiat no provision for ad.- justment of the valve movement be made but that the valve be confined to a fixed throw the exact length of which is best determined by experimentation for each size of pump and valve and the size of the steam inlet but in any event the movement is very short so as to form a narrow annular inlet which will not direct the steam down against the surface of the water or localize the entrance jet, the object in avoiding such conditions being to preserve as far as possible a placid surface on the water in the cylinder whereby condensation of the steam is in a large measure prevented.

When manual manipulation of the throttle valve is resorted to to prime or start the pump, advantage is taken of the fact that when the steam is turned on there will be a slight leakage into the cylinder under the inlet valve and if the throttle valve be closed the steam in the cylinder will condense through contact with the cylinder walls thereby creating a partial vacuum and inspiration of water through the inlet. The throttle may be closed several times if found necessary to start the pump into operation although under ordinary circumstances when water stands in the out-take the pump will start up at once when the steam is turned on and will run continuously so long as the steam supply is kept up. A reduction in the water supply does not stop the pump but the regulation is automatic, a water supply less than the capacity of the pump simply operating to reduce the speed of operation and only partially, instead of fully, filling the cylinder.

What I claim as new and desire to secure by Letters Patent, is:

1, In a steam vacuum pump, the comhination with the cylinder having valved intake and out-take connections at the bottom and means for producing periodic condensation of the steam in the cylinder, of a steam inlet at the top of the cylinder, and a piston valve controlling said steam inlet having its only opposing piston faces exposed to the cylinder pressure and atmospheric pressure respectively when the valve is in both open and closed positions, whereby variations between atmospheric and cylinder pressure cause the valve to open and close Without regard to the pressure in the steam supply.

2. In a steam vacuum pump, the combinaas soon I tion with the cylinder having valved intake and out-take connections at the bottom and means for producing periodic condensation of the steam in the cylinder, of a cylindrical piston valve having one face exposed to at mospheric pressure when both open and closed and a single opposing face exposed to the pressure in the cylinder when both open and closed and a steam inlet controlled by the movement of the valve, said valve being uninfluenced by variations of pressure in the steam supply.

v3. In a steam vacuum pump, the combination with the cylinder having valved intake and out-sane connections at the bottom and means for producing periodic condensation of steam in the cylinder, of a cylindrical piston valve of uniform diameter, a cylindrical casing in which the valve works at all times, open at the top to atmosphere and at the bottom to the cylinder and having an intermediate steam supply passage closed to the atmosphere at all times by the valve and opened to the cylinder by the raising of the valve due to variation between the cylinder and atmospheric pressure.

4. In a steam vacuum pump, the combination with the cylinder having valved intake and out-take connections at the bottom and means for producing periodic condensation of steam in the cylinder, of a steam inlet at the top of the cylinder, a cylindrical piston valve of uniform diameter having a plane face exposed to the cylinder, an annulus forming the bottom of the steam inlet passage and on which the valve seats, a cylindrical casing in which the valve works extending above the steam inlet and open to the atmosphere above the valve when the valve is in both open and closed positions.

5. In a steam vacuum pump, the combination with the cylinder having valved intake and out-take connections at the bottom, of a valve casing having a cylindrical bore, a lateral steam entrance terminating in an annular channel at one end of the bore, a cylindrical valve of uniform diameter working in the bore of the casing and a flat annulus clamped between the end of the casing and cylinder and forming the lower wall of the annular steam passage and seat for the end of the cylindrical valve.

WILLIAM R. EMERSOW.

/Vitnesses:

ALEXANDER S. STEUART, THoMAs DURANT. 

